Greek yogurt is awesome, but calorie dense. My wife eats the strawberry/honey variant and, if my memory at work serves me correctly, it was somewhere near 450 calories per 1/2 cup.

I do plain with a bit of honey.

My current weakness: Kartofflsalat, vegetarian veggie soup and the banana pudding at Jason's Deli. It's cheap, fills me up and, while I know it's not amazingly healthy, a good choice when I'm on the go. My staple diet if all else fails: Hold yo' breathe - bean and cheese burrito, fresco still, grilled from Taco Bell. It's sadly 100 times healthier than most people think and tastes pretty good with hot sauce. Also, I've been able to master eating one while out on 30+ milers knowing that I can always trust to find a Taco Bell.